Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 261950

Area Forecast Discussion
National Weather Service Lincoln IL
250 PM CDT MON SEP 26 2016

.SHORT TERM...(This evening through Tuesday)
ISSUED AT 250 PM CDT Mon Sep 26 2016

A cold front has moved through the Midwest and cooler and drier air
has settled in behind the front.  As a result, quiet weather and
cooler temperatures will continue through the overnight.  Tonights
lows will drop into the 40s...chilly by comparison to the weather of
late. Tomorrow will climb back into the upper 60s and low to mid
70s. Skies should remain clear as dry air and subsidence generally
rules.  The pressure gradient should keep the winds relatively
breezy out of the WNW.


.LONG TERM...(Tuesday night through Monday)
ISSUED AT 250 PM CDT Mon Sep 26 2016

Cooler than normal conditions will dominate the extended forecast,
as an occluded low pressure system drifts from the western Great
Lakes south toward Indiana/Ohio. The trend in the last couple of
runs of the models has been a farther west track of the low, closer
to Illinois. The ECMWF was the first to show that trend, and the
others have shifted in that direction. The EC remains the farthest
west with where the low lingers this week. It is also the last to
eject the low to the east next Saturday, although the Canadian and
GFS are not nearly as far behind as previous model runs.

The overall effect of a westward shift in the low placement would
mean much cloudier conditions in Illinois, at the very least. It
could also mean more days with the potential for periodic showers as
spokes of energy rotate around the cut-off low. We previously just
had slight chance PoPs on Tuesday night into Wednesday. However, the
influence of the EC model on the blended extended has prompted
additional slight chances for rain east of Bloomington to Decatur,
from Thursday night through Saturday. Friday shows the farthest west
expansion of rain chances, reaching all the way to Peoria and
Springfield. The forecast soundings are minimally supportive of rain
at any point this week, with a narrow layer of moisture in the lower
levels the primary moisture source. So rainfall amounts would be
trace amounts to a few hundredths of an inch for any areas that do
get rain this week and next weekend.

As mentioned previously, temps will linger below normal for the
first time in months. Morning lows on Wednesday will dip into the
upper 40s to low 50s. Mostly cloudy conditions on Wednesday will
keep highs that day limited to the mid to upper 60s, our coolest day
of the next week. The lingering proximity of the low just to the
east of Illinois the rest of the week will allow the chilly air mass
to linger. Highs Thursday through Saturday should remain in the
lower 70s, with lows in the lower 50s. At this point, more sunshine
is expected on Thursday, with increasing clouds Friday and Saturday.
With the forecast eastward departure of the low by Sunday, high
temps should climb a few degrees toward the mid 70s Sunday, with mid
to upper 70s next Monday.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1232 PM CDT Mon Sep 26 2016

High pressure moving in with significantly drier air resulting in
SKC, and breezy W/NW winds. Keeping the gusts up throughout the
day with the mixing down of some stronger 20-25 kt winds just off
the sfc. Losing gusts around sunset, and clear skies through the
overnight as well. VFR throughout.


.ILX Watches/Warnings/Advisories...


LONG TERM...Shimon
AVIATION...HJS is the U.S. government's official web portal to all federal, state and local government web resources and services.